Diphenoxylate is a structural analog of ________ which is chemically a ________.

Diphenoxylate is a structural analog of ________ which is chemically a ________.

• A. Meperidine; phenylpiperidine
• B. Pethidine; pyridine
• C. Methadone; phenylheptylamine
• D. Pentazocine; benzomorphan

Answer: (A)

Diphenoxylate is built on the same chemical scaffold as certain opioid analgesics, sharing the phenylpiperidine framework. Meperidine (also called pethidine) is a classic opioid whose core structure is a phenylpiperidine. Because diphenoxylate mirrors that same core, it’s best described as a structural analog of meperidine, which is chemically a phenylpiperidine. That’s why the pairing meperidine with phenylpiperidine is the correct choice. The other options mix in different chemical families—methadone has a phenylheptylamine backbone, pentazocine is a benzomorphan, and while pethidine is another name for meperidine, it would be incorrect to describe it as pyridine, since the correct ring is piperidine, not pyridine.

Diphenoxylate is built on the same chemical scaffold as certain opioid analgesics, sharing the phenylpiperidine framework. Meperidine (also called pethidine) is a classic opioid whose core structure is a phenylpiperidine. Because diphenoxylate mirrors that same core, it’s best described as a structural analog of meperidine, which is chemically a phenylpiperidine. That’s why the pairing meperidine with phenylpiperidine is the correct choice.

The other options mix in different chemical families—methadone has a phenylheptylamine backbone, pentazocine is a benzomorphan, and while pethidine is another name for meperidine, it would be incorrect to describe it as pyridine, since the correct ring is piperidine, not pyridine.